16.000 years of being the most fel-corrupted planet besides Sargeras himself.
If there are any pockets of beauty left, then fel is bullshit. Fel is poison. You die, or live to become a monster. If there is beautiful wildlife and left on Argus, a literal giant burning fel coal of a planet, then the universe just doesn't make sense. The whole point of the Burning Legion is the death of everything. From the biggest creature to the smallest microbe. If they can't even accomplish that on their most tainted world, then the Legion is bullshit.